Illustrator Thomas Nast depicted conditions before emancipation, left, and afterward, right. A former slave’s home is in the center. (Getty Images)

On New Year's Day 1863, Quinn Chapel, a black church in Chicago, hosted a celebration of the Emancipation Proclamation. According to the Tribune's account, after Scripture was read and the choir sang, J. Stanley recited a poem he'd written for the occasion, "What It Is to Be a Slave." He started with a question:

Oh! What is a slave? 'Tis to tremble with dread,

And bow to the despot an infamous head;

And when he has spurned thee, to beg and implore,

That he in his kindness would trample thee more.

.

'Tis to gaze in despair on the sun's living ray,

Like a thing without soul or a creature of clay;

To lose all affection and sympathy dear,

And all passions of man — save the passion of fear.

Abraham Lincoln's executive order freeing the Confederacy's slaves had just gone into effect, triggering a mass movement of Southern blacks rejecting fear and embracing hope. Wherever Union troops appeared, their ranks would be swollen by African-Americans abandoning plantations where they and their ancestors had been held in bondage. It began as a trickle but quickly became a flood. Already on Jan.16, the Tribune was reporting Virginia's slaves were on the move: "In farm wagons, in coaches, on horseback, afoot and in buggies with valuable property, in every case, this second movement from Egypt to the promised land fills the highways and the woods."

In the Oscar-nominated film "Lincoln," Daniel Day-Lewis portrays the president as he fights in 1865 to get the 13th Amendment, abolishing slavery, passed in the U.S. House. The movie focuses on political struggles in the Capitol. But ordinary men and women were making a social revolution, inspired by Lincoln's bold proclamation of 1863. The Civil War had become a war against slavery, and the United States was a nation on the move.

As Gen. Nathaniel Banks' regiments marched through Louisiana 150 years ago, they were greeted by slaves musically mocking their former owners — "Massa run away, hi, hi!!" — and celebrating freedom with biblical images:

"I think dat now de Kingdom come,

Dat dis de year of Jubile!"

Strange as it now seems, Southerners were stunned when blacks voted for freedom with their feet in the third year of the Civil War. One of the intellectual underpinnings of slavery was a fantasy that happy-go-lucky African-Americans were content to toil for others' benefit. Desperate for an explanation of what had gone wrong, some slave owners blamed religion, as the Tribune noted in November 1863, quoting a Virginia newspaper. "Upon the last appearance of the Yankees at Fredericksburg the only negroes who went off with them when they retired were those who belonged to, or were frequenters of, the African church there," the Richmond Whig reported. "This is bad for the Christian religion."

By September 1863, some residents of Southern and border states were conceding that slavery was a lost cause, as the Tribune reported of a group of Missouri tobacco growers: "They called their slaves together, informed them of their design and told them if they would work faithfully until the stock of tobacco was manufactured, they would be free."

Not all slaves were offered such generous terms, even by Northern whites. Union soldiers could be just as racist as the Confederates. Some officers refused to feed them, or give them medical care in the wake of a deadly smallpox epidemic. Other Union officers were more pragmatic and enrolled ex-slaves in their brigades.

For Southerners, the sight of black troops was a portent of defeat, as the Tribune noted in an 1864 report from North Carolina: "Proudscions of chivalry, accustomed to claim the most abject obedience from their slaves, literally fell on their knees before these armed and uniformed blacks, and begged for their lives."

As things worked out, the Emancipation Proclamation and the 13th Amendment didn't remove the stain of racism. Starting in 1876, Southern blacks were subjugated by Jim Crow laws that mandated segregation, necessitating a second struggle for freedom during the civil rights movement nearly a century later.

But by the last year of the Civil War, the African-American community of Charleston could write slavery's death certificate with a massive parade.

"Next in order came the Twenty-first regiment United States Colored Troops, Lieut.-Col. Bennett commanding, preceded by a band," a Tribune correspondent wrote. "A company of school boys, the leading boy carrying a banner with the device, 'We know no masters but ourselves,' followed the military."

A few days after that April 1865 parade, Lincoln was assassinated, and the Tribune reflected on the bittersweet meaning of his death for the slaves he had freed: "From all parts of the South, four millions of humble simple men and women who have never known national calamity before, now feel their deep interest in the nation's loss."

Even earlier, the Tribune noted how a group of blacks freed from chains and shackles in a Baltimore slave market paid tribute to the Great Emancipator, as others knew him.

"In the evening one of the Lieutenants, talking with the new freedmen, asked them if they knew the person who liberated them. 'No,' answered one, 'we don't know him, but we know that God sent him.' 'Yes,' echoed the rest, 'God sent him — God sent him!'"